Do bent valves always present with bad lash?

[tastyratz]

so my s14 with 155k drove perfectly fine, idled fine, averaged 27mpg, and had no noticeable ticking or loss of power.

I parked the car Friday night and went to start it Monday morning, I heard a burble trying to start then a terrible sound... the sound of no compression.
Confirmed with a compression tester:

1. 90
2. 90
3. 40
4. 40

I started thinking I bent valves (but on interference I would think 1&3 and 2&4 would pair similar results?)
I checked valve lash. This car has a redrilled cam gear and 248 exhaust on the intake, with 232 exhaust cam swap... from about 10k miles ago. I wont lie I did the swap without checking valve lash so I don't know how close it was before... but spec is 13-16 thousandths and I was mostly within... with a couple 10s and a couple 18s on a completely cold engine - most likely ALL within spec.

Has anyone ever seen a bent valve that presented in spec lash?

The only thing I can think of is jumping a timing chain tooth.

Worst part?


THIS IS THE SECOND TIME. I had the SAME EXACT PROBLEM on a completely different s14 with a different KA. ran fine till on day nothing.

Before anyone asks: cam was the proper 6 links + 2 links (4 teeth) for the exh swap +2 more links for the 2.5 degree adv cam gear position.

What gives? Thoughts?

[Pro ViZIon]

Have you messed with anything?

If you had the cam swap going for a good 10k miles then im sure that shouldnt be your issue. Have you opened it up to check it out?

[tastyratz]

Haven't touched anything on the car probably in 7 or 8k miles or so.

I did pull the valve cover off to measure lash. Visually it SEEMS ok...

Not looking forward to pulling the pan/front cover/etc to check timing or potentially pulling the head.

[Pro ViZIon]

You don't need to take off the front cover to check. Just the upper timing cover.

[daryl337]

so my s14 with 155k drove perfectly fine, idled fine, averaged 27mpg, and had no noticeable ticking or loss of power.

I parked the car Friday night and went to start it Monday morning, I heard a burble trying to start then a terrible sound... the sound of no compression.
Confirmed with a compression tester:

1. 90
2. 90
3. 40
4. 40

I started thinking I bent valves (but on interference I would think 1&3 and 2&4 would pair similar results?)
I checked valve lash. This car has a redrilled cam gear and 248 exhaust on the intake, with 232 exhaust cam swap... from about 10k miles ago. I wont lie I did the swap without checking valve lash so I don't know how close it was before... but spec is 13-16 thousandths and I was mostly within... with a couple 10s and a couple 18s on a completely cold engine - most likely ALL within spec.

Has anyone ever seen a bent valve that presented in spec lash?

The only thing I can think of is jumping a timing chain tooth.

Worst part?


THIS IS THE SECOND TIME. I had the SAME EXACT PROBLEM on a completely different s14 with a different KA. ran fine till on day nothing.

Before anyone asks: cam was the proper 6 links + 2 links (4 teeth) for the exh swap +2 more links for the 2.5 degree adv cam gear position.

What gives? Thoughts?




Theoretically speaking it could be possible. Realistically? I would not say so.
The chances of all 4 cylinders to present similar symptoms, *and* measure close to spec is slim to none if you were dealing with bent valves. Is this an NA set up, or turbo?

[Hashiriya415]

You should use a leak down tester. And start pulling the head off, at the end no matter what you do or how you diagnose, typing up stuff on forums, it won't change compression readings.
Valves could burn up, proper clearance lets valves touch head to cool off. If you no longer have that and they are not touching the head, they will run hot and burn/crack.

[tastyratz]

You think I could check it out with just the upper timing cover? Can I see the crank snub teeth from there? Ill give it a shot tonight.

If I don't have to pull the head I would be more than relieved too, because it's just another expense (when I need to pay for dyno time on my s13)

Just count links on the chain? Does anyone know how many there should be?

[tastyratz]

pulled upper cover and verified cam timing is CORRECT for upper cams. To avoid having to pull the whole bottom half apart...

Does anyone have a lower chain around not installed or an open front ka?
How many links are there between the gold links on each side?

I should be able to count the teeth and rotate the engine as I go. If I count the teeth I should be able to ensure the idler pulley is proper compared to the lower without ever cranking it all open (since the gold teeth are just for reference)

[Pro ViZIon]

there should be six links between the to marked ones.

Like Hashiria415 said you should perform a leakdown test first. Then go ahead and take the head of if you need to.

[mxexux]

Cylinder Leak Down Tester!!! Save your self the headache. The tester will make it obvious if the valves are bent without having to count links and such nonsense.

[thatfastteg]

it really sounds like you skipped the chain on the crank gear. maybe your tensioner took a shit. roll it up to tdc and see where the cams are at. all your numbers would be that low. it would be really hard to bend a valve in each cyl. sounds like a timing issue.

[Pro ViZIon]

I've bent valves on my car. Had compression similar to yours cylinder 2 had 50 and cyl 3 had 90.

[Hashiriya415]

Look at cam lobe I2 and E3, thats piston 1 TDC
http://i124.photobucket.com/albums/p6/Hashiriya415/Car/BluKA24DE.jpg

http://i124.photobucket.com/albums/p6/Hashiriya415/Car/BluKA24DE4-1.jpg